Slow and fast light in pyramid shaped quantum dots under applied electric fields: The effect of the incident light polarization

Abstract

Simultaneous effects of the electric field and the incident light characteristics (photon frequency, optical intensity and ellipticity parameter) on the optical properties of a pyramid shaped quantum dot have been investigated. Within the density matrix approach, the light absorption, the refractive index as well as the group velocity near the dot resonance energies are discussed. We found that (i) the slow and fast light are optically controllable not only by changing the probe intensity, but also by varying the polarization direction of the light and the ellipticity parameter; (ii) the magnitude of the group index can reach significant values for a circularly polarized photon field and (iii) the sub- and super-luminal frequency intervals increase with the growth in the ellipticity parameter. The control of the group velocity can be also achieved by applying a static electric field which induces significant changes in the resonant peak position and the group index magnitude.